[GROOVY-7058] NPE when using type parameter in trait method

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.3.6
• Fix Version/s: 2.3.7
• Component/s: groovy-runtime
• Assignee: Cédric Champeau
• Reporter: Peter Niederwieser
• Created: 05/Sep/14 14:05
• Updated: 17/Dec/14 13:25
• Resolved: 25/Sep/14 07:11

Description

I'm trying to mix a trait into a Gradle plugin. This works:

trait PluginUtils {
    abstract Project getProject()
    
    public <T extends Task> T createTask(String name, Class type, Closure<?> config) {
      project.task(name, type: type, config)
    }
}

class MyPlugin implements Plugin<Project>, PluginUtils {
    Project project
    
    void apply(Project project) {
        this.project = project
        createTask("foo", DefaultTask) {}
    }
}

apply plugin: MyPlugin

As soon as I change Class to Class<T> in the signature of the createTask method, gradle foo blows up with:

Caused by: java.lang.NullPointerException
	at com.sun.beans.TypeResolver.resolve(TypeResolver.java:203)
	at com.sun.beans.TypeResolver.resolve(TypeResolver.java:218)
	at com.sun.beans.TypeResolver.resolve(TypeResolver.java:169)
	at com.sun.beans.TypeResolver.resolve(TypeResolver.java:218)
	at com.sun.beans.TypeResolver.resolveInClass(TypeResolver.java:96)
	at MyPlugin.<clinit>(/swd/tmp/traitplugin/build.gradle)

Tested with Gradle 2.1-rc-4/Groovy 2.3.6 and Gradle 2.0/Groovy 2.3.3.